Airfoil structure

ABSTRACT

An airfoil is provided by distorting a relatively stiff piece of a solid material. One starts with an elongated thin, stiff material and forms a gore in the trailing surface and then at least partially closes the gore. This distorts the thin material into a stable, airfoil configuration.

United States Patent Laurent [4 1 Apr. 4, 1972 AIRFOIL STRUCTURE [72] Inventor: Andre J. M. Laurent, Box 586, Los

Alamos, Calif. 93440 [22] Filed: Oct. 13, 1970 [21] Appl. No.: 80,463

Related US. Application Data [63] Continuation of Ser. N01 764,181, Oct. 1, 1968, abandoned.

[56] References Cited UNITED STATES PATENTS 1,227,319 5/1917 Robbins 46/79 2,005 ,842 6/ 1935 Marcus 46/ 76 2,472,137 6/1949 Winslow..... ...244/153 2,708,330 5/1955 Ciampolini ..46/79 3,010,250 11/1961 Houston, Jr. ..46/79 Primary Examiner-Louis G. Mancene Assistant ExaminerD. L. Weinhold Attorney-Eckhoff and Hoppe [57] ABSTRACT An airfoil is provided by distorting a relatively stiff piece of a solid material. One starts with an elongated thin, stiff material and forms a gore in the trailing surface and then at least partially closes the gore. This distorts the thin material into a stable, airfoil configuration.

3 Claims, 7 Drawingfigures AIRFOIL STRUCTURE This is a streamlined continuation of application Ser. No. 764,181 filed Oct. 1, 1968.

SUMMARY OF THE INVENTION Heretofore airfoils have ordinarily been made by providing a material of substantial thickness. Another form of airfoil comprises a thin sheet of material which is held to a desired curve with some form of bracing. In accordance with the present invention an airfoil is provided of very simple structure wherein one merely takes the sheet of material which has some thickness and forms a gore in the trailing surface thereof and then closes the gore at least partially. This distorts the material to an aerodynamically stable airfoil form.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a toy airplane embodying the airfoil structure of the present invention.

FIG. 2 is a section on the line 2-2 of FIG. 1.

FIG. 3 is a partial view of a wing showing a gore cut therein preparatory to fonning the airfoil.

FIG. 4 is a view similar to FIG. 3 wherein the gore has been closed, causing the material to form the desired airfoil.

FIG. 5 shows an embodiment of the invention having means for varying the curvature of the airfoil to any desired degree.

FIG. 6 shows how the airfoil of the present invention can be formed simply by folding a sheet of paper.

FIG. 7 shows an airfoil having a novel strut arrangement.

DESCRIPTION OF THE PREFERRED EMBODIMENTS In forming an airfoil it was previously thought necessary to either provide a sheet of material with some bracing or to build up a thick structure of the desired airfoil shape. In accordance with the present invention, it has been found that an airfoil can be made quite simply merely by providing a gore in the trailing edge of a stiff material and then closing the gore at least partially. Surprisingly, as one closes such a gore, the material from which the wing is built distorts and assumes a very stable aerodynamic configuration.

In order to construct such a wing or airfoil, one ordinarily starts with an elongated piece of material, generally in the form of an airplane wing which is several times as long as it is wide, which has bilateral symmetry and which has a certain degree of stiffness. The exact shape of the airfoil is not critical and it can be in the form of a rectangle, a rectangle with rounded ends, a tapered configuration or other configurations as is well known to those skilled in the art of winged designs. One of the long edges is designated a trailing edge while the opposite edge is a leading edge. A gore is then cut in the center of the trailing edge.

This can best be seen in FIGS. 3 and 4. Thus, in FIG. 3, a wing 7 has a leading edge 9 and a trailing edge 11. A gore is of triangular shape with the apex of the V pointing toward leading edge as shown. The exact shape and size of the gore will depend upon how deeply one wishes to form the airfoil but normally it will encompass more than half of the width of the wing. In FIG. 4, the structure is shown after the gore has been closed. Any suitable means can be used to hold the gore in a closed or partially closed position such as glue or a clamp. In FIG. 4, edges have been merely butt glued together as at l5.

In FIG. 1 there is shown a practical embodiment of the invention wherein a wing 17 has had a gore cut at the trailing edge thereof and the gore closed as at 19. The arrows 21 illustrate the force necessary to hold the gore in a closed position. In this case, the airplane has also been provided with a fuselage 23, a propeller 25, and a tail structure 27. The aerodynamic shape can be seen in the sectional view of FIG. 2.

Another embodiment of the invention is shown in FIG. 5 wherein a wing structure 29 has a gore 31 cut therein and a small turnbuckle 33 is used to pull the edges of the gore toward each other. By the use of a turnbuckle or a similar adjustable means, one can secure varying degrees of lift from the wirl g structure. t

G. 6, shows how an airfoil embodying the present invention can be made from a sheet of paper or similar material merely by folding it. Here the wing 35 has a gore 37 folded therein and the excess material as at 39 is not removed but is merely folded upon itself and, in fact, can be glued together and used as the fastening means to keep the airfoil in its stressed form.

In FIG. 7 a novel strut arrangement is shown. Here struts 41 and 43 are shown joined to a central member 45. It can be seen that as the gore 47 is closed there will be a greater curvature of the wings, which would tend to weaken them. However, as the gore is closed, greater tension is put on struts 41 and 43 tending to strengthen the wing.

Although certain specific embodiments of this invention have been disclosed, it will be understood that these are for illustration purposes only and that many variations can be made without departing from the spirit of this invention.

For instance, the airfoil can be made from various materials so that a thin sheet of wood, metal, plastic, paper, cardboard or the like is suitable. The wing structure should be symmetrical but within this limitation can assume various forms such as that of a rectangle, tapered rectangle, or a figure with a straight leading edge and a tapered trailing edge or the like.

I claim:

1. An airfoil structure comprising a generally elongate, thin, stifi material having bilateral symmetry and an elongate leading edge and an elongate trailing edge; a V-shaped gore in the center of the trailing edge with the apex of the V extending toward the leading edge but terminating short of the leading edge; and means for readily opening and closing the gore to distort the airfoil into a stable, self-supporting airfoil shape, said means enabling the characteristics of the airfoil to be readily altered.

2. An airfoil structure as in claim 1, wherein said means comprises an adjustable turnbuckle fastened at opposite ends thereof to opposing facing edges of said gore to adjust the spacing between said opposing facing edges.

3. An airfoil structure comprising a generally elongate, thin, stiff material having bilateral symmetry and a leading edge and a trailing edge; a V-shaped gore cut in the center of the trailing edge with the apex of the V pointing toward and terminating short of the leading edge and having opposing facing spaced edges; and an adjustable turnbuckle connected at its opposite ends to the opposing facing edges of said V-shaped gore to selectively vary the spacing between said spaced edges to distort the wing into different, stable, self-supporting airfoil shapes. 

1. An airfoil structure comprising a generally elongate, thin, stiff material having bilateral symmetry and an elongate leading edge and an elongate trailing edge; a V-shaped gore in the center of the trailing edge with the apex of the V extending toward the leading edge but terminating short of the leading edge; and means for readily opening and closing the gore to distort the airfoil into a stable, self-supporting airfoil shape, said means enabling the characteristics of the airfoil to be readily altered.
 2. An airfoil structure as in claim 1, wherein said means comprises an adjustable turnbuckle fastened at opposite ends thereof to opposing facing edges of said gore to adjust the spacing between said opposing facing edges.
 3. An airfoil structure comprising a generally elongate, thin, stiff material having bilateral symmetry and a leading edge and a trailing edge; a V-shaped gore cut in the center of the trailing edge with the apex of the V pointing toward and terminating short of the leading edge and having opposing facing spaced edges; and an adjustable turnbuckle connected at its opposite ends to the opposing facing edges of said V-shaped gore to selectively vary the spacing between said spaced edges to distort the wing into different, stable, self-supporting airfoil shapes. 